Dunn, 22, is tall, with a slender body and full chest. The fashion industry has long been criticized for favoring waif-like models who tend to have slim hips and small busts. Many claim the industry trend leads to eating disorders among models as well as to unrealistic body image expectations in average girls and women.

"They definitely missed out by not booking her because I think she would have looked amazing in his clothes and would have been beautiful in the show," said Cynthia Bailey, owner of Atlanta's The Bailey Agency School of Fashion.

Detractors have labeled model Kate Upton fat, and others question whether her lush figure belongs on a high-fashion runway. Upton acknowledged that some of the comments were difficult to handle but, she said, she has learned to take it in stride.

Dunn seemed to take a lighthearted approach to the loss, Sunday tweeting, "I'm normally told I'm cancelled because I'm 'coloured' so being cancelled because off my boobs is a minor : )"

The fashion industry has been heavily criticized for the lack of diversity in runway models and Christian Dior, the venerable fashion house that Dunn claims cancelled her, is no stranger to that criticism.

In a March interview with Buzzfeed, James Scully, a casting director who works with top designers including Tom Ford, Stella McCartney and Jason Wu, shared his impressions of the lack of multicultural representation on the couture runway.

"Some of the biggest names who move fashion to the forefront, like Dior, get a 'D-minus' on ethnic diversity," Scully said, referring to the last fashion season. "I feel the Dior cast is just so pointedly white that it feels deliberate. I watch that show and it bothers me. I almost can't even concentrate on the clothes because of the cast."

At least one fashion insider says Dior, who did not respond to ABC News' request for comment, has the right to choose who represents its fashion line.

"In the end of the day, they are selling clothes and they are projecting an image and it's their prerogative," said Erin Busbee, the owner of Busbee Style, a fashion consulting company. "It is their right to say, 'She is not right for us.'"